Auxin is a positive regulator for ethylene-mediated response in the growth of arabidopsis roots
Auxin is a positive regulator for ethylene-mediated response in the growth of arabidopsis roots
复制标题
DOI：
10.1093/pcp/pce035
复制
发表时间：
2001-03-01
影响因子：
4.9
通讯作者：
Tsurumi, S
中科院分区：
文献类型：
--
作者：
Rahman, A;Amakawa, T;Tsurumi, S
利用两个乙烯抗性突变体aux 1 -7和eir 1 -1研究了拟南芥幼苗根中乙烯介导的生长反应对生长素的需求，这两个突变体的根已被证明分别在生长素流入和流出载体中存在缺陷。在野生型根中，用0.84穆尔升（-1）乙烯可达到50%的生长抑制（I-50），但在eir 1 -1根中诱导I-50需要71.3穆尔升（-1）乙烯。在aux 1 -7根中，即使在1，000 μ l穆尔升-1乙烯下也得不到I-50。相反，在10 nM l-萘乙酸（NAA）存在下，eir 1 -1和aux 1 -7根中诱导I-50所需的乙烯浓度大大降低，接近野生型根中所需的水平。细胞内生长素水平的增加可能是乙烯反应恢复的原因。NAA在10 nM时不抑制根的生长单独应用时，但它是最佳浓度，以恢复乙烯反应的突变体根。这些结果表明，生长素是一个积极的调节乙烯诱导抑制根伸长。
The requirement of auxin for the ethylene-mediated growth response in the root of Arabidopsis thaliana seedlings was investigated using two ethylene-resistant mutants, aux1-7 and eir1-1, whose roots have been shown to have a defect in the auxin influx and efflux carriers, respectively. A 50% inhibition of growth (I-50) was achieved with 0.84 mul liter(-1) ethylene in wild-type roots, but 71.3 mul liter(-1) ethylene was required to induce I-50 in eir1-1 roots. In aux1-7 roots, I-50 was not obtained even at 1,000 mul liter-1 ethylene. By contrast, in the presence of 10 nM l-naphthaleneacetic acid (NAA), the concentrations of ethylene required to induce I-50 in eir1-1 and aux1-7 roots were greatly reduced nearly to the level required in wild-type roots, Since the action of NAA to restore the ethylene response in aux1-7 roots was not replaced by IAA, an increase in the intracellular level of auxin is likely to be the cause for the restoration of ethylene response. NAA at 10 nM did not inhibit root growth when applied solely, but it was the optimum concentration to recover the ethylene response in the mutant roots. These results suggest that auxin is a positive regulator for ethylene-induced inhibition in root elongation.